1. Field of the Invention
The present invention relates to a rotary connector device supplied for electrical connection between a vehicle body and a steering wheel in an automobile or the like.
2. Description of Related Art
Japanese Patent Laid-Open No. 11-204224 discloses a conventional rotary connector device shown in FIG. 4. This rotary connector device 101 is provided with a fixed-side housing 105 having an outer tubular wall 103 and a movable-side housing 109 having a inner tubular wall 107. A moving body 117 is rotatably arranged in an accommodating section 111 formed between the fixed-side housing 105 and the movable-side housing 109. The moving body 117 is provided with a first opening 113 and a second opening 115. First and second flat cables 119 and 121 are wound in the accommodating section 111 in such a manner that both ends of each of the first and second flat cables 119 and 121 are fixed respectively on circumferential surfaces of the outer tubular wall 103 and inner tubular wall 107 and reversing sections 119a and 121a of the both the flat cables 119 and 121 pass through the first opening 113 and the second opening 115.
When a steering wheel is rotated, this rotation is transmitted to the movable-side housing 109 to rotate the movable-side housing 109 in the same direction. For example, when the movable-side housing 109 rotates in the clockwise direction, the reversing sections 119a and 121a of the first and second flat cables 119 and 121 rotate and move in the clockwise direction by a rotary amount smaller than that of the movable-side housing 109, and the moving body 117 also rotates and moves in the clockwise direction in response to the motion of the reversing sections 119a and 121a. As a result, the first and second flat cables 119 and 121 are reeled out by a length about twice as long as the moving amount from the side of the inner tubular wall 107 and are rewound back to the side of the outer tubular wall 103, so that the first and second flat cables 119 and 121 are in a rewound state. In this case, the reversing section 119a of the first flat cable 119 moves in the first opening 113 in the clockwise direction. At this point the reversing section 121a of the second flat cable 121 moves in the second opening 115 in the clockwise direction, but since a width dimension W1 of the first opening 113 and a width dimension W2 of the second opening 115 are configured to have a relation of W1<W2, only the reversing section 119a in the first opening 113 having the shorter width dimension presses a fixed tube 123 as a guide section in the clockwise direction, and the reversing section 121a in the second opening 115 having the longer width dimension does not press a fixed tube 125. Therefore, the moving body 117 rotates in the accommodating section 111 by receiving only the pressing force from the reversing section 119a of the first flat cable 119.
In contrast, when the movable-side housing 109 rotates in the counterclockwise direction from a neutral state of the steering wheel, the reversing sections 119a and 121a of the first and second flat cables 119 and 121 rotate and move in the counterclockwise direction by a rotary amount smaller than that of the movable-side housing 109, and the moving body 117 also rotates and moves in the counterclockwise direction in response to the motion of the reversing sections 119a and 121a. As a result, the first and second flat cables 119 and 121 are reeled out by a length about twice as long as the moving amount from the side of the outer tubular wall 103 and are wound up to the side of the inner tubular wall 107, so that the first and second flat cables 119 and 121 are in a wound-up state. In this case also, only the reversing section 119a in the first opening 113 having the shorter width dimension pulls a roller 127 as a guide section opposing the fixed tube 123, and therefore, the moving body 117 rotates in the accommodating section 111 by the tension force.
In this way, in the clockwise direction operation of the steering wheel, the reversing section 119a of the first flat cable 119 moves in the first opening 113 having a width of W1 and thereafter, contacts against the fixed tube 123, and in the counterclockwise direction operation of the steering wheel, the reversing section 119a moves in the first opening 113 having a width of W1 in the opposite direction and thereafter, contacts against the roller 127. Each contact of the reversing section 119a in the first flat cable 119 rotates and moves the moving body 117 in the clockwise direction or in the counterclockwise direction, thus making it possible to smoothly operate the rotary connector device 101.
However, since the rotary connector device 101 is so configured that the reversing section 119a moves in the first opening 113 of W1 and thereafter, contacts against the fixed tube 123 or the roller 127, thus operating the rotary connector device 101, an interference noise of the reversing section 119a with the fixed tube 123 or the roller 127 is possibly generated.
Therefore, in the conventional rotary connector device, when a driver turns a steering wheel of an automobile backward, an impact noise is generated, therefore raising the problem of giving discomfort to the driver as an abnormal sound. That is, the conventional rotary connector device has the problem that since the reversing section moves and thereafter, contacts against the guide section, thereby operating the rotary connector device, the interference noise of the reversing section with the guide section is possibly generated.
In view of the above, there exists a need for a rotary connector device which overcomes the above mentioned problems in the conventional art. The present invention addresses this need in the conventional art as well as other needs, which will become apparent to those skilled in the art from this disclosure.